Assembly For Placing A Prosthetic Valve In A Duct In The Body

ABSTRACT

The present invention is an assembly comprising a prosthetic valve to be implanted; a radially expandable stent comprising at least one zone intended to be expanded to allow the stent, in the expanded state, to bear against the wall of the body duct to be fitted with the valve, this bearing making it possible to immobilize this stent with respect to this wall; and means for mounting the valve with respect to the stent, making it possible to connect the valve to the stent in such a way that the placement of the stent allows the valve to be mounted in the body duct, and expansion means such as a balloon catheter being provided to trigger expansion of the stent at the implantation site. According to the invention, the valve and the stent are designed in such a way that, at the moment when the stent is expanded, the valve is situated outside the zone or zones of the stent that are subjected to said expansion means. The invention thus consists in separating the valve and said zone or zones to be expanded, so that the expansion of the stent can be effected with an expansion force suitable for perfect anchoring of this stent in the wall of the body duct to be fitted with the valve, and without any risk of destruction or damage of the valve.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.11/829,682, filed Jul. 27, 2007, which is a continuation of U.S.application Ser. No. 10/482,270, filed Jul. 6, 2004, now U.S. Pat. No.7,252,682, which is the U.S. national phase under §371 of InternationalApplication No. PCT/FR02/02352, filed on Jul. 4, 2002, which waspublished in a language other than English and which claimed priorityfrom French Application No. 01/08898, filed on Jul. 4, 2001, thedisclosures of which are hereby incorporated by reference in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an assembly for placing a prostheticvalve in a lumen of the body, especially a heart valve, and inparticular an aortic valve.

2. Background Art

Documents WO 91/17720, WO 98/29057 and EP 1 057 460 each describe anassembly, including the prosthetic valve to be implanted; a radiallyexpandable framework, called a stent, which is able, in the expandedstate, to bear against the wall of the body duct to be fitted with thevalve, this bearing making it possible to immobilize this stent withrespect to this wall; and means for fixing the valve to the stent. Theplacement of the stent permits mounting of the valve in the body duct,eliminating the need for an external access route and, thus, a directsurgical intervention.

However, major drawbacks of this technique are that it entails a risk ofthe valve being damaged by the balloon used to expand the stent, and itlimits the force of expansion that can be imparted to the stent. Thislimitation has repercussions on the anchoring of the stent, making adisplacement of said assembly possible. This limitation also hasrepercussions on the leaktightness of the stent in the area of thevalvular ring which is particularly affected when calcified zones givethe valvular ring an irregular form and/or a certain rigidity.

Another drawback of the prior art technique is that of directly joiningthe commissures of the valvules to the stent. The result of this is thatan expansion of the stent, and thus of the valve, different than thatintended may cause poor coaptation of the valvules and, consequently,defective functioning of the valve. The stent therefore has to undergo apredetermined expansion, which prevents or complicates adaptation ofthis stent to the anatomical variations.

In the case of implantation of an aortic valve, the prior art techniquealso has drawbacks in that it necessitates very exact positioning of thestent in the aorta so that the valve is located opposite the naturalvalvular ring, and it entails a risk of blocking the apertures of thecoronary arteries that open out at the coronary ostia.

BRIEF SUMMARY OF THE INVENTION

The present invention aims to overcome these various drawbacks. Theassembly of the present invention comprises a prosthetic valve to beimplanted; a radially expandable framework, or stent, comprising atleast one zone intended to be expanded to allow the stent, in theexpanded state, to bear against the wall of the body duct to be fittedwith the valve, this bearing making it possible to immobilize the stentwith respect to this wall; and means for mounting the valve with respectto the stent, making it possible to connect the valve to the stent insuch a way that the placement of the stent allows the valve to bemounted in the body duct, and expansion means such as a balloon catheterbeing provided to trigger expansion of the stent at the implantationsite. According to the invention, the valve and the stent are designedin such a way that, at the moment when the stent is expanded, the valveis situated outside the zone or zones of the stent that are subjected tosaid expansion means. The invention thus consists in separating thevalve and said zone or zones to be expanded, so that the expansion ofthe stent can be effected with an expansion force suitable for perfectanchoring of this stent in the wall of the body duct to be fitted withthe valve, and without any risk of destruction or damage of the valve.

According to one possibility, the stent comprises a zone for mounting ofthe valve, which zone is distinct from the zone or zones of the stent tobe expanded, and said mounting means connect the valve to this mountingzone. The expansion of the stent thus triggers the deployment of thevalve.

According to another possibility, said mounting means are designed insuch a way that the valve is axially movable with respect to the stentbetween a position of non-implantation, in which it is situated outsidethe zone or zones of the stent that are to be expanded, and a positionof implantation, which it can reach after expansion of the stent in thebody duct, in which it is immobilized axially with respect to the stent.

The valve can thus form a subassembly separate from the stent prior toplacement of this stent in the body duct, and it can be placed in thestent once the latter has been implanted. Alternatively, the valve isconnected to the stent before said stent is placed in the body duct tobe treated, and consequently it is introduced into this duct with thestent; said mounting means then comprise means of displacement so that,once the stent has been expanded, the valve can be displaced betweensaid position of non-implantation and said position of implantation.

Said mounting means can then comprise one or more of the followingarrangements:

-   -   fastening members such as spikes, hooks or claws that are        mounted on the valve and are able to be inserted into the wall        delimiting said body duct; these fastening members can be        oriented radially with respect to the valve so as to be able to        be inserted into said wall upon radial deployment of the valve,        or they can be oriented tangentially with respect to the valve        so as to be able to be inserted into said wall upon a pivoting        of the valve about its axis or upon a longitudinal movement with        respect to the stent;    -   burstable vesicles that are filled with biological adhesive or        other suitable adhesive product and are placed on the outer face        of the valve, these vesicles being able to burst when the valve        is brought into its position of implantation, in particular by        their being crushed between the valve and the stent;    -   at least one circular or helical wire or band integrated in the        peripheral wall of the valve and having a shape memory, so that        it keeps the valve pressed against the stent in the position of        implantation of this valve;    -   conduits formed in, or fixed on, the peripheral wall of the        valve, and rods formed on the stent, or vice versa, these rods        being able to be engaged and being able to slide through these        conduits as the valve moves from its position of        non-implantation to its position of implantation, it being        possible to provide means such as hooks in order to immobilize        these conduits with respect to these rods in said position of        implantation; wires can be connected to the ends of said rods        and can pass through said conduits in order to easily guide        these rods in these conduits.

Preferably, the means for mounting the valve with respect to the stentare designed in such a way that, beyond a threshold of expansion of thestent, they permit a different expansion of the valve and of the stent,so that a variation in the degree of expansion of the stent has noeffect on the degree of expansion of the valve.

The valve is thus not connected directly to the stent and in particularis not connected to the stent in the area of the commissures of itsvalvules; in the expanded position of the stent, it can have apredetermined diameter appropriate to it, independently of the diameterof the stent. After implantation, the valve thus has a configurationensuring that it functions properly irrespective of the degree ofexpansion of the stent, and this expansion of the stent can be adaptedto the anatomical variability encountered at the implantation site.

The stent and/or the valve can comprise one or more elements limitingthe maximum diameter of expansion of the valve, in particular in thearea of the commissure points of this valve. These elements can belongitudinal wires belonging to the stent, or a framework elementbelonging to the valve.

Preferably, the valve has a peripheral wall with a diameter not constantin the axial direction, in particular a frustoconical shape whosediameter decreases in the distal direction, and the zone of the stentintended to receive this peripheral wall of the valve has a shapecorresponding to that of this peripheral wall. This peripheral wall andthis zone of the stent thus define a determined position of mounting ofthe valve in the stent, and they ensure that the valve is held inposition in the stent. The stent advantageously has a middle portionwith a smaller diameter than its end portions. It can in particular havethe general form of two inverted truncated cones or an hourglass shape.

In the case where the assembly according to the invention permitsmounting of an aortic valve, the stent is thus at a distance from thewall of the body duct, in particular by means of a conical or hourglassshape, allowing body fluid to pass to the coronary vessels in the areaof the coronary ostia. The valve has a shape corresponding to that zoneof the stent in whose area it is intended to be mounted.

Advantageously, the valve has a peripheral wall; the stent has, in thedistal continuation of that zone of the stent intended to receive thevalve, a foldable portion; this foldable portion is movable between anextended position, in which it is situated in the distal continuation ofsaid zone, and a folded position, in which it is placed against theinner face of the peripheral wall of the valve and traps this peripheralwall between it and said zone of the stent, and retaining means areprovided for keeping this foldable portion in this folded position. Theperipheral wall of the valve is thus pressed against the stent, whichensures leaktightness of the valve with respect to the stent.

According to a preferred embodiment of the invention in this case, saidretaining means are formed by a wire made of a material that is rigidbut has a degree of elastic flexibility, for example a metal materialhaving an undulated form and extending over the entire circumference ofsaid foldable portion. Preferably, the stent comprises a sheath made ofan impermeable biocompatible material and at least partially coveringit. This sheath forms a fixation base for the valve and at the same timea means of sealing between the stent and the wall of the body duct. Thesheath can advantageously have lateral openings that can be positionedopposite the coronary ostia at the time of implantation and thus avoidany zone of stagnation or non-circulation of the blood.

Advantageously, in the case where the assembly according to theinvention comprises said foldable portion, this foldable portion isformed by a continuation of said sheath, forming a sleeve beyond thatzone of the stent intended to receive the valve. Perfect leaktightnessis thus obtained between the valve and the stent. The stent preferablyhas, fixed on said sheath, at least one inflatable peripheral chamberthat can be inflated in order to form a seal ensuring leaktightnessbetween the stent and the wall of the body duct to be fitted with thevalve. This leaktightness is thus guaranteed notwithstanding thepossible presence of calcified portions that give a cardiac ring anirregular shape.

Advantageously in this case, the stent has two inflatable peripheralchambers placed either side of that portion of the stent intended tobear against a cardiac valvular ring. The stent can have a cylindricalportion that can bear against a cardiac valvular ring, and a distalportion connected to this cylindrical portion. This distal portion atleast partially forms said zone intended to receive the peripheral wallof the valve. The advantage is that said wall of impermeablebiocompatible material is situated, in the area of this portion, at adistance from the wall of the body duct, that, in the case ofimplantation of an aortic valve, eliminates the risk of masking thecoronary ostia.

The stent can also have a frustoconical or widened proximal portionwhose diameter decreases in the distal direction and able, in the caseof implantation of a heart valve, to bear against the wall of theventricle or corresponding auricle of the heart. With this proximalportion it is possible to define the position of the stent, and thussubsequently of the valve, with respect to the zone of implantation. Italso helps ensure complete immobilization of the stent. The stent canalso have a supplementary bearing portion connected by filiform rods tosaid distal portion or to said cylindrical portion, these filiform rodshaving lengths such that this supplementary bearing portion ispositioned beyond the coronary ostia. According to an additionalcharacteristic, the stent has hooks that are movable between a retractedposition, which they occupy before expansion of the stent, and aposition of deployment into which they are brought upon deployment ofthe stent and in which they are inserted into a wall delimiting the bodyduct.

The stent can also have a portion near to the valvular ring, or situatedopposite or on this valular ring, and having a high radial force, thatis to say a radial force able to erase the local anatomicalirregularities, for example calcifications, with a view to reinforcingthe leaktightness at the junction between the stent, the sheath and thewall of the treated duct. This portion can be deployed with the aid ofan expansion system with a high radial force and low compliance, forexample a balloon.

The above embodiments and methods of use are explained in more detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

FIG. 1 is a side view of an expandable framework called a stent, whichforms part of the assembly;

FIG. 2 is a longitudinal section through a sheath forming part of theassembly, according to a first embodiment;

FIG. 3 is a longitudinal section through a heart valve forming part ofthe assembly, according to this first embodiment;

FIG. 4 is view of a detail of the stent, on an enlarged scale;

FIG. 5 is a view of another detail of the stent, on an enlarged scale,in a state of non-expansion of the stent;

FIG. 6 is a view of the same detail, in cross section along the lineVI-VI in FIG. 5;

FIG. 7 is a view similar to FIG. 5, in a state of expansion of thestent;

FIG. 8 and [sic] a view of the same detail, in cross section along theline VIII-VIII in FIG. 7;

FIG. 9 is a longitudinal section through the assembly according to theinvention, after implantation in an aorta;

FIG. 10 is a longitudinal section through the sheath and the valveforming part of the assembly according to the invention, in a secondembodiment, with the catheter used for introducing the valve into thissheath;

FIG. 11 is a perspective view of the valve according to the secondembodiment;

FIG. 12 is a view similar to FIG. 10, after placement of the valve;

FIG. 13 is a view, similar to FIG. 9, of the assembly according to athird embodiment;

FIG. 14 is a perspective view of the valve that can be placed in thestent shown in FIG. 13, and

FIGS. 15 through 17 are views of the assembly according to the thirdembodiment, in cross section on lines XV-XV, XVI-XVI and XVII-XVII,respectively, in FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

In embodiments described herein, those elements or parts that areidentical or similar and are found again from one embodiment to anotherare designated by the same reference numbers.

FIGS. 1 through 3 show, respectively, an expandable framework 2 called astent, a sheath 3, and a prosthetic valve 4. This stent 2, this sheath 3and this valve 4 form an assembly 1, which can be seen in FIG. 9,allowing the valve 4 to be placed in an aorta 100, showing the locationof the coronary ostia 101 and the origin of the coronary vessels 104.

Referring to FIG. 1, it will be seen that the stent 2 comprises insuccession, from one axial end to the other, in the proximal to distaldirection, a frustoconical proximal portion 10, a proximal cylindricalportion 11, a distal frustoconical portion 12, several connection rods13, and a distal cylindrical portion 14.

This stent 2 is made of a metal, steel or alloy with shape memory. Thisshape-memory material can in particular be the one known by the brandname Nitinol.

The portions 10 through 12 and 14 are made up of a network of filamentsforming juxtaposed meshes of diamond shape or, for portion 10, oftriangle shape. The material from which the stent 2 is made is such thatthese meshes can pass from a contracted configuration, in which thefilaments are near one another, giving the meshes an elongate shape, toan expanded configuration, shown in FIG. 1 and in detail in FIG. 7, inwhich the filaments are spaced apart from one another.

In the contracted configuration, the assembly 1 can be introduced intothe aorta 100 by means of a catheter, as far as the zone in which theprosthetic valve 4 is to be implanted; in the expanded configuration,the stent 2 bears against the aorta 100, the wall 102 of the ventricleand the natural valvular ring 103 in the manner shown in FIG. 9, suchthat it permits implantation of the valve 4 in place of the naturalvalve, the latter having been removed beforehand if necessary.

Referring to FIGS. 1 and 9, it will be seen that the portion 10 has adiameter decreasing in the distal direction, this portion 10 beingconfigured so that, in the expanded state, it bears against the wall 102of the ventricle of the heart.

In the expanded state, the portion 11 has a diameter such that it isable to bear against the natural valvular ring 103 and a radial forcesuch that it can push the natural valve (or its remnants after partialexeresis) against the ring 103 in order to ensure leaktightness at thissite. This portion 11 has deployable hooks 15, shown more particularlyin FIGS. 5 through 8. These hooks 15 permit anchoring of the stent 2 inthe aorta 100 via the sheath 3.

As is shown in FIGS. 5 and 6, each hook 15 extends in the longitudinaldirection of a mesh, being connected in a pivotable manner to a proximalzone 16 of connection of two proximal filaments 17. This hook 15 has acurved and tapered free end 15 a, and a face 15 b directed to the insideof the stent 2 and of rounded shape. The distal zone 18 of connection ofthe two other filaments 19 that is situated opposite the base of thehook 15 is able to bear, during expansion of the stent 2, on this face15 b, as will be inferred from comparison of FIGS. 6 and 8. The factthat this zone 18 bears along this face 15 b makes it possible to deploythe hook 15 radially outward of the stent 2 and maintain this hook 15 inthe deployed position in which its tapered end 15 a is inserted into thewall of the ring 103. The hooks can have a fishhook shape in order toprevent their removal.

The portion 12 is directly connected to the portion 11 and has adiameter decreasing in the distal direction. This portion 12 is intendedto extend to the area of the coronary ostia 101 and to receive the valve4. Its frustoconical shape means it is possible to keep the sheath 3 ata distance from the coronary ostia 101 and thus prevent any risk ofcovering the apertures 104 of the coronary vessels that open out inthese.

The portion 12 additionally comprises a series of internal arms 25,shown more particularly in FIG. 4. Each arm 25 is connected via itsproximal end to a junction zone 16 of two proximal filaments 17 of amesh, in proximity to the portion 11, and has a curved distal end 25 a.These arms 25 are inclined toward the inside of the portion 12 beforeplacement of the valve 4 on the stent 2, and FIG. 4 shows that in thisposition they can receive the valve 4. The latter actually comprises aperipheral wall 30 in which there are longitudinal tunnels 31 forreceiving the arms 25; these can then be folded back against the wall ofthe portion 12, either by deformation of the material constituting thearms 25 and/or the portion 12, or by shape memory when use is made of amaterial with shape memory. These arms 25 thus allow the valve 4 to bemounted in the portion 12, as is shown in FIG. 9.

The connection rods 13 connect the distal edge of the portion 12 to theproximal edge of the portion 14. They are arranged uniformly on theperiphery of the stent 2 and, as is shown in FIG. 9, they have a lengththat is sufficient to ensure that the portion 14 is placed, afterimplantation, beyond the coronary ostia 101. The spacing of these rods13 can be curbed by an annular element making it possible to limit theupper diameter of the valve 4 to a predefined size.

The portion 14 for its part has, in the expanded state, a slightlygreater diameter than the internal diameter of the aorta 100, and itbears against the wall of the latter once the stent 2 has been put inplace. This portion 14 can be equipped with hooks 15.

The sheath 3 is made of an impermeable biocompatible material, such aspericardial tissue, material known under the name Dacron, or a polymersuch as polyurethane, and it has portions 35, 36 and 37. These portions35, 36 and 37 can be connected, respectively, to the portions 10, 11 and12 and can closely match these portions 10 through 12 when the latterare in the expanded state. The connection between the sheath 3 and theportions 10 through 12 is formed by seams when the assembly 1 isassembled. The connection can also be effected by molding of a polymermaterial.

At the proximal end, the sheath 3 has a flap 40 extending on the outerface of the portion 35. This flap 40 has, near its free edge, aninflatable peripheral chamber 41. This chamber 41 can be inflated so asto form a seal ensuring leaktightness between the sheath 3 and the wallof the ventricle 102, on the proximal side of the natural valvular ring103.

At the distal end, the sheath 3 has a flap 42 extending on the outerface of the portion 12. Near its free edge, this flap 42 comprises aninflatable peripheral chamber 43, similar to the chamber 41 and able tobe inflated in the same way as the latter. This chamber 43 ensuresleaktightness between the sheath 3 and the ring 103, on the distal sideof the latter.

It will be seen from FIG. 2 that the flap 42 forms a distal sleeve 45extending beyond the distal edge of the portion 12, and it is clear fromFIG. 9 that this sleeve 45 can be folded back inside the portion 12.This sleeve 45 includes a metal wire 46 extending over the entirecircumference, this wire 46 having an undulated shape and beingelastically deformable. The deformability of this wire 46 allows thesleeve 45 to pass from its extended position shown in FIG. 2 to itsfolded position shown in FIG. 9, in which it is maintained by elasticreturn of the wire 46. In this folded position, the sleeve 45 is placedagainst the inner face of the peripheral wall 30 of the valve 4 andtraps this wall 30 between it and said portion 12.

The valve 4 can be made of a biological material or of a syntheticmaterial, or of a combination of these two types of materials. Itsperipheral wall 30 has a frustoconical shape adapted to its tightengagement in the portion 12 when the arms 25 are folded back againstthis portion 12, which ensures complete immobilization of the valve 4 inthe stent 2.

The assembly 1 is assembled by placing the sheath 3 on the stent 2 andplacing the valve 4 on the arms 25, the stent 2 being in the contractedstate. The assembly 1 is then placed in a catheter permitting itsintroduction into the patient's body, this catheter including one ormore inflatable balloons able to deploy the portions 10, 11 and 14. Thiscatheter is then brought into position in the aorta 100. The balloonsare then inflated in order to deploy the portions 10, 11 and 14; theforced deployment of the portion 11 by the balloons ensures thedeployment of the hooks 15 and triggers deployment of the portion 12,and consequently of the valve 4. The chambers 41, 43 are then inflatedto ensure leaktightness of the sheath 3 with respect to the ring 103,and the sleeve 45 is folded back inside the portion 12 in order to clampthe peripheral wall 30 of the valve 4 against this portion 12.

As will be apparent from the above, the valve 4 and the stent 2 of theassembly 1 are designed in such a way that the valve 4 is situatedoutside the zone or zones 10, 11, 14 to be expanded. The stent 2 can beexpanded with a force of expansion adapted for perfect anchoring of thisstent 2 in the receiving walls 100, 102, 103, and without any risk tothe valve 4. The hooks 15 ensure complete immobilization of the assembly1 in the aorta 100, and the chambers 41, 43, and also the sleeve 45,ensure complete leaktightness of the assembly 1 with respect to theaorta 100.

In the second embodiment of the assembly 1, the valve 4 is not mountedin advance inside the stent 2 but is placed in it once the stent 2 hasbeen expanded. As is shown in FIG. 10, the sheath 3 then has internaltubes 50 formed in such a way as to protrude inside the stent 2 oncethis sheath 3 is engaged on the stent 2. These tubes 50 can inparticular be sewn or fixed by any other means to the sheath 3 after thelatter has ben placed on the stent 2.

Referring to FIG. 11, it will be seen that the peripheral wall 30 of thevalve 4 has, in place of the tunnels 31, a series of pin-shaped clips51. Each clip 51 has an inner arm 52 engaged longitudinally in the wall30, and a rectilinear outer arm 53 extending along the outer face of thewall 30. The arms 53 terminate in curved ends and are connected to wires55 engaged and able to slide in the tubes 50.

As is shown in FIG. 10, a catheter 80 is used to bring the valve 4 intoposition in the sheath 3. The valve 4 is engaged with sliding on thecatheter 80, and the wires 55, after passing through the tubes 50, areengaged in the catheter 80 from the direction of the distal openingthereof and pass through this catheter 80 in order to be actuated fromthe outside. The valve 4 is put into place and deployed by pulling onthe different wires 55 so as to engage the different arms 53 in thetubes 50. The inner arms 52 can comprise (see FIG. 12) proximal hooksthat complete the deployment of the valve 4 by being fastened to thewall of the sheath 3, for example by means of inflation of a balloon.

In the third embodiment of the assembly 1 shown in FIG. 13, the stent 2forms a median cage delimited by a ring 60 and by longitudinal wires 61,in which cage the valve 4 is tightly inserted. As is shown in FIG. 14,the valve 4 has a lateral wall 30 of tubular shape in which threelateral openings 65 are formed. These openings 65 are positionedopposite the coronary ostia 101 and permit a natural flow of blood,without risk of stagnation in the area of these coronary ostia 101.

The invention provides an assembly 1 for placing a valve 4 in a bodyduct 100, said assembly having the following advantages over similarassemblies in the prior art: elimination of the risk of damage to thevalve 4 by the balloon or balloons used to expand the stent 2;possibility of applying a considerable force of expansion to the stent2, that ensures the anchoring of the assembly 1; this considerable forceof expansion additionally permits this anchoring by means of thedeployable hooks 15; elimination of the risk of dilation of the valve 4beyond a diameter no longer permitting its optimal functioning, inparticular through loss of coaptation of the valvules; possibility ofobtaining perfect leaktightness of the assembly 1 in the area of thevalvular ring 103 and of the valve 4; elimination of the risk ofblocking of the coronary ostia 101; and maintenance of a flow of bodyfluid all around said assembly 1 once the latter is implanted.

It goes without saying that the invention is not limited to theembodiment described above by way of example, and that instead itencompasses all alternative embodiments thereof coming within the scopeof protection defined by the attached claims.

It is to be appreciated that the Detailed Description section, and notthe Summary and Abstract sections, is intended to be used to interpretthe claims. The Summary and Abstract sections may set forth one or morebut not all exemplary embodiments of the present invention ascontemplated by the inventor(s), and thus, are not intended to limit thepresent invention and the appended claims in any way.

The present invention has been described above with the aid offunctional building blocks illustrating the implementation of specifiedfunctions and relationships thereof. The boundaries of these functionalbuilding blocks have been arbitrarily defined herein for the convenienceof the description. Alternate boundaries can be defined so long as thespecified functions and relationships thereof are appropriatelyperformed.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the invention that others can, by applyingknowledge within the skill of the art, readily modify and/or adapt forvarious applications such specific embodiments, without undueexperimentation, without departing from the general concept of thepresent invention. Therefore, such adaptations and modifications areintended to be within the meaning and range of equivalents of thedisclosed embodiments, based on the teaching and guidance presentedherein. It is to be understood that the phraseology or terminologyherein is for the purpose of description and not of limitation, suchthat the terminology or phraseology of the present specification is tobe interpreted by the skilled artisan in light of the teachings andguidance.

The breadth and scope of the present invention should not be limited byany of the above-described exemplary embodiments, but should be definedonly in accordance with the following claims and their equivalents.

The claims in the instant application are different than those of theparent application or other related applications. The Applicanttherefore rescinds any disclaimer of claim scope made in the parentapplication or any predecessor application in relation to the instantapplication. The Examiner is therefore advised that any such previousdisclaimer and the cited references that it was made to avoid, may needto be revisited. Further, the Examiner is also reminded that anydisclaimer made in the instant application should not be read into oragainst the parent application.

1. A prosthetic valve assembly comprising: an implantable prostheticcardiac valve configured to permit blood flow in a first direction andto inhibit blood flow in a second direction opposite to the firstdirection; and a radially expandable annular support comprising a firstinflatable peripheral chamber and a second inflatable peripheralchamber, wherein the first and second inflatable peripheral chambers areeach configured to bear against a wall of a native body lumen when in aninflated stated, and wherein the annular support has a central lumen forpermitting blood flow therethrough when the annular support is in anexpanded position, wherein the valve is mounted on the annular support,and wherein the valve assembly is configured to delivered bycatheterization.
 2. The assembly of claim 1, wherein the secondinflatable chamber is configured to bear against the wall of the aortaproximal to a native valvular ring when in its inflated state.
 3. Theassembly of claim 1, wherein the first inflatable chamber is configuredto bear against the wall of a ventricle proximal to a native valvularring when in its inflated state.
 4. The assembly of claim 1, wherein thefirst inflatable chamber is configured to bear against the nativevalvular ring.
 5. The assembly of claim 1, wherein the second inflatablechamber is configured to bear against the native valvular ring.
 6. Theassembly of claim 1, wherein the annular support is formed generally inan hourglass shape.
 7. The assembly of claim 1, wherein the annularsupport is formed at least partially of a biocompatible polymer.
 8. Theassembly of claim 7, wherein the first and second inflatable chambersare formed of a biocompatible polymer.
 9. The assembly of claim 1,wherein the first and second inflatable chambers are configured toprevent leakage between the annular support and the native valvularring.
 10. The assembly of claim 2, wherein the second inflatable chamberis configured such that it is below the coronary ostia and does notobstruct the coronary arteries when in the inflated state.
 11. Theassembly of claim 1, wherein, when the annular support is in theexpanded position, the valve is substantially within the native valvularring.
 12. The assembly of claim 1, wherein the annular support has adifferent diameter at the location of the first inflatable chamber thanat the location of the second inflatable chamber when the annularsupport is in the expanded position.
 13. The assembly of claim 12,wherein the annular support has a larger diameter at the location of thefirst inflatable chamber than at the location of the second inflatablechamber when the annular support is in the expanded position.
 14. Aprosthetic valve assembly comprising: a prosthetic cardiac valveconfigured to replace the function of a natural cardiac valve; and aradially expandable tubular support having a distal inflatable chamberand a proximal inflatable chamber connected thereto, wherein the distalinflatable chamber is configured to bear against a wall of an aorta inan inflated state, and wherein the proximal inflatable chamber isconfigured to bear against a wall of a ventricle in an inflated stated,wherein the prosthetic cardiac valve is mounted on the tubular support,and wherein the valve assembly is configured to delivered bycatheterization.
 15. The assembly of claim 14, wherein the tubularsupport has a different diameter at the location of the proximalinflatable chamber than at the location of the distal inflatable chamberwhen the tubular support is in an expanded position.
 16. The assembly ofclaim 15, wherein the tubular support has a larger diameter at thelocation of the proximal inflatable chamber than at the location of thedistal inflatable chamber when the tubular support is in the expandedposition.
 17. The assembly of claim 14, wherein the distal inflatablechamber is configured such that it is below the coronary ostia and doesnot obstruct the coronary arteries when in the inflated state.
 18. Theassembly of claim 14, wherein the distal and proximal inflatablechambers are configured to prevent leakage between the tubular supportand a native valvular ring.
 19. The assembly of claim 14, wherein, whenthe tubular support is in an expanded position, the valve issubstantially within a native cardiac valvular ring.